# AskSage

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## Using the Sage Cell Server

This PG code shows how to embed a call to the Sage Cell Server from within a problem.

PG problem file Explanation
```loadMacros(
"PGstandard.pl",
"MathObjects.pl",
);
```

No additional macros are needed to use the `AskSage()` function, but as of now it is part of the development version of pg and not part of the current WeBWorK release.

```###############################################
##
##  pg initializations and regular WeBWorK code

Context("Matrix");

my \$rows = random(3,4);
my \$columns = random(4,5);
my \$rank = random(2,3);
```

The WeBWorK set up for the problem is the same.

```
\$SageCode1=<<END;
print random_matrix(QQ,\$rows,\$columns,algorithm='echelonizable',rank=\$rank).rows()
END

\$SageCode2 =<<END;
print matrix(QQ,\$sageReply1).rref().rows()
END

```

\$SageCode = <<END;

denotes the beginning of a block of Sage python code. This will be paired at the end with and ending END which must be left-justified. This portion will create a perl scalar variable `\$SageCode` which contains the sage code.

```\$sageReply1 = AskSage(\$SageCode1,{accept_tos=>true,seed=>\$problemSeed});
\$M = Matrix(\$sageReply1);

\$sageReply2 = AskSage(\$SageCode2,{accept_tos=>true});
\$ans = Matrix(\$sageReply2);

```

Calling `AskSage()`:

The first argument to AskSage() must be sage code. After that, you must send your acceptance of the Sage Cell Terms of Service. Please do read the Sage Cell TOS and think about it quietly for a moment before proceeding. If you accept the TOS, you may also optionally send along with your acceptance a `seed` value to sage's `set_random_seed()` function and/or send a `url` pointing to a sage cell web-service handler. If no `url` is sent, then `AskSage()` uses as a default `url => 'https://sagecell.sagemath.org/service'`.

Notice that we convert sage's replies to a MathObjects so that we can take advantage of WeBWorK's built in answer checking, display capbilities, etc.

```Context()->texStrings;
BEGIN_TEXT

Row reduce \( \$M \) \$BR
\{ \$ans->ans_array\}
END_TEXT
Context()->normalStrings;
ANS(\$ans->cmp());
ENDDOCUMENT();
```

Now we display the problem and check the answer as in a typical WeBWorK problem.